DEBUGFS (8)
ext2 file system debugger
SYNOPSIS
debugfs
[
-f
cmd_file
]
[
-R
request
]
[
-V
]
[
-w
[
device
]
]
DESCRIPTION
The
debugfs
program
is a file system debugger. It can be used to examine and change the
state of an ext2 file system.
device
is the special file corresponding to the device containing the ext2
file system (e.g /dev/hdXX).
OPTIONS
-w
Specifies that the file system should be opened in read-write mode.
Without this option, the file system is opened in read-only mode.
-f cmd_file
Causes
debugfs
to read in commands from
cmd_file ,
and execute them. When
debugfs
is finished executing those commands, it will exit.
-R request
Causes
debugfs
to execute the single command
request ,
and then exit.
-V
print the version number of
debugfs
and exit.
COMMANDS
debugfs
is an interactive debugger. It understands a number of commands.
cat filespec
Dump the contents of the inode
filespec
to stdout.
cd filespec
Change the current working directory to
filespec .
chroot filespec
Change the root directory to be the directory
filespec .
close
Close the currently open file system.
clri file
Clear the contents of the inode
file .
dump [-p] filspec out_file
Dump the contents of the inode
filespec
to the output file
out_file .
If the
-p
option is given set the owner, group and permissions information on
out_file
to match
filespec .
expand_dir filespec
Expand the directory
filespec .
feature [fs_feature] [-fs_feature] ...
Set or clear various filesystem features in the superblock. After setting
or clearing any filesystem features that were requested, print the current
state of the filesystem feature set.
find_free_block [goal]
Find the first free block, starting from
goal
and allocate it.
find_free_inode [dir [mode]]
Find a free inode and allocate it. If present,
dir
specifies the inode number of the directory
which the inode is to be located. The second
optional argument
mode
specifies the permissions of the new inode. (If the directory bit is set
on the mode, the allocation routine will function differently.)
freeb block
Mark the block number
block
as not allocated.
freei filespec
Free the inode specified by
filespec .
help
Print a list of commands understood by
debugfs (8).
icheck block ...
Print a listing of the inodes which use the one or more blocks specified
on the command line.
initialize device blocksize
Create an ext2 file system on
device
with device size
blocksize .
Note that this does not fully initialize all of the data structures;
to do this, use the
mke2fs (8)
program. This is just a call to the low-level library, which sets up
the superblock and block descriptors.
kill_file filespec
Deallocate the inode
filespec
and its blocks. Note that this does not remove any directory
entries (if any) to this inode. See the
rm (1)
command if you wish to unlink a file.
ln filespec dest_file
Create a link named
dest_file
which is a link to
filespec .
Note this does not adjust the inode reference counts.
ls [-l] filespec
Print a listing of the files in the directory
filespec .
modify_inode filespec
Modify the contents of the inode structure in the inode
filespec .
mkdir filespec
mknod filespec [p|[[c|b] major minor]]
Create a special device file (a named pipe, character or block device).
If a character or block device is to be made, the
major
and
minor
device numbers must be specified.
ncheck inode_num ...
Take the requested list of inode numbers, and print a listing of pathnames
to those inodes.
open [-w] [-f] device
Open a filesystem for editing. The
-w
flag causes the filesystem to be opened for writing. The
-f
flag forces the filesystem to be opened even if there are some unknown
or incompatible filesystem features which would normally
prevent the filesystem from being opened.
pwd
Print the current working directory.
quit
rm pathname
Unlink
pathname .
If this causes the inode pointed to by
pathname
to have no other references, deallocate the file. This command functions
as the unlink() system call.
rmdir filespec
Remove the directory
filespec .
This function is currently not implemented.
setb block
Mark the block number
block
as allocated.
seti filespec
Mark inode
filespec
as in use in the inode bitmap.
show_super_stats [-h]
List the contents of the super block and the block group descriptors. If the
-h
flag is given, only print out the superblock contents.
stat filespec
Display the contents of the inode structure of the inode
filespec .
testb block
Test if the block number
block
is marked as allocated in the block bitmap.
testi filespec
Test if the inode
filespec
is marked as allocated in the inode bitmap.
unlink pathname
Remove the link specified by
pathname
to an inode. Note this does not adjust the inode reference counts.
write source_file out_file
Create a file in the filesystem named
out_file ,
and copy the contents of
source_file
into the destination file.
SPECIFYING FILES
Many
debugfs
commands take a
filespec
as an argument to specify an inode (as opposed to a pathname)
in the filesystem which is currently opened by
debugfs .
The
filespec
argument may be specified in two forms. The first form is an inode
number surrounded by angle brackets, e.g.,
<2> .
The second form is a pathname; if the pathname is prefixed by a forward slash
('/'), then it is interpreted relative to the root of the filesystem
which is currently opened by
debugfs .
If not, the pathname is
interpreted relative to the current working directory as maintained by
debugfs .
This may be modified by using the
debugfs
command
cd .
AUTHOR
debugfs
was written by Theodore Ts'o <tytso@mit.edu>.
SEE ALSO
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